Process of distilling and purifying fatty materials



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E@ w3., D. 5. @Emma w PROCESS .0F DSTILLING AND'IPURIFYING FATTY MATERIALS Filed May 20, `1929 2 Sheeefsmhee 2 Cwvpevvsffe Patented May 16, 19.33

UNITED STATES PATENT OFFICE .DANIEL S; BELLEN, OF LOS ANGELES, CALIFORNIA, ASSIGN'OR TO FILTROL COMPANY OF CALIFORNIA, F LOS ANGELES, CALIFORNIA, A CORPORATION 0F CALIFORNIA PROCESS OF `DIS'LILLINGr AND PURIFYING FATTY MATERIALS Application 1ed May 20,

This invention relates toa process of distilling free fatty acids, particularly oleic, palmitic and stearic acids or mixtures of them, from mixtures of free fatty acids, or4 mixtures of ixed fats with free fatty acids.

Among theobjects of thevinventio-n is the simultaneous decolorization, purification and distillation of the fatty materials. Another objrrect is the avoidance of the production oflarge amounts of iso-oleic or hydrostearic acids, such as may occur in distillation processes using direct superheated steam.

Briefly stated, my process comprises distilling the fatty acids or the like from an acid-proof still while bubbling through them a lively stream of an inert gas, such as carbon dioxide or nitrogen. Experience has shown that steam is not entitled to be called inert. At the same time, the acids are brought' into contact with an adsorbent, preferably ofthe acid-activated clay type. Such ladsorbent may either be contained within the still or may be contained in a tower or dephlegmator so that the" acids may be acted upon while they 'e are in the vapor phase. The distillation is preferably carried out under as high a vacuum as possible, but permissibly under atmospheric pressure when fatty acids only are being distilled.

In order to' carry out my process wherein the adsorbent is in contact with the liquid fatty material during distillation, I may make use of an apparatus of the kind shown in Fig. 1, which is a side elevational view and is more or less diagrammatic.v f

For distillation with contact in the vapor phase with the adsorbent, I may use the-ap-v paratus shownin Fig. 2, which is also a side elevation, also somewhat diagrammatic.

In both figures, 10 represents the body of the still, 11 its residue discharge pipe, 12- a cleaning manhole. 13 a. liquid level gauge, 14 a vacuum-breaking valve, 15 a pressure gauge, 16 a thermometer, 17 an inlet pipe for fatty material, 18 a vapor outlet pipe havingtherein a sight glass 19.l and 20/a. supply pipe for inert gas, said pipe extending almost to the bottomfof the still and ter- .ininating in a gas-distributing ring 21.. The

1929. Serial N0., 364,455.'

still is provided with a steam jacket, not shown, or equivalent heating means.

Inert gas may be supplie-d to the still from a cylinder 22 of compressedgas, which is connected 4to the pipe 20 at 23. A check valnve-24f is provided inthe pipe 2O behind the point 23 to prevent flow of gas in an undesired direction. The pipe 20, before it enters the still, passes through a heater 25, containing a steam coil 26' or equivalent heating means. The heater 25 and the remainder of the pipe 20 are preferably heat insulated up to thepoint where that pipe enters the still.

. In Fig.l 1, the vapor exit pipe 18 of the still connects with an air condenser 27 of the type which is conventional for this kind of work, it consisting of a number of vertical lengths of pipe connected by return bends 28. The end of the last vertical pipe is connected by ymeans of a pipe 29 to a vacuum pump 30. To the middle of the lower return bends 28 there are connected anl equal number of condensing coils 31, one tol each bend. The coils are vertically arranged within a cooling box 32 which is provided with a cooling water inlet 33 and outlet. A water level may be maintained about coils 31 or not, as preferred. The lower ends of the coils 31 are each connected to a manifold 34 and are each provided with control valves 35.v One or more receivers 36 are coupled to the manifold 34 and are pro-` either to the atmosphere or into a storage reservoir 40 for inert gas. A compressor 41 is adapted to take gas from the reservoirv and to lreturn it to the still through the rige y he apparatus shown 1n Flg. 2 1s dliferent from that of Fig. 1 only in that a vapor re- {ining column 50 is interposedbetween the stilland the air condenser. For this purpose a straight vertically-disposed pipe 51,

suitablyheat insulated, leads'from the still to the bottom of the column 50. Within .the Amo,

column 50, a plurality of shelves 52 extends or cloth is a layer of adsorbent clay notA more than two inches in thickness and preferably onl about 3%; inch thick. The number of suc shelves is to be governed by the kind of material worked upon, the efficiency of the bleaching material and other factors,

but will ordinarily be from four to ten.

Any desired number may be used.

The top shelf has above the layer of adsorbent a protecting porous plate 53 which is rovided to prevent particles of the adsor ent from being carried over into the condenser.

The bottom of the column is preferably made conical and provided with a drip pan '54 having a central opening 55. Connected f theretovis an' outside return pipe 5G leading to the still, to provide for return of condensate.

In operating the apparatus of Fig. l in the purification of fatty material in the liquid phase, one proceeds as follows: From 5% to 20% of adsorbent clay'by weight of the fatty material to be distilled (in this case assumed to be free fattyacid) is charged into the still. The melted fatty material is then run in through the pipe 17. The still is then heated and the vacuum pump 30 is operated to exhaust the air within the-apparatus to the atmosphere through the three-Way valve 39. After a high degree of vacuum has been obtained the valve 39 is turned to exhaust anyl remaining gas into the storage reservoir 40. The valve 24 is then closed if manual operation thereof is required, and inert gas is allowed to run into the pipe 20 from the cylinder 22. Carbon dioxide or nitrogen are the gases preferred for this purpose. Steam is admitted to the heatlng coil 26 to preheat the gas supply. A lively but not violent stream of gas is supplied through the pipe 20 to the now boiling contents'of the still which are continuously kept under reduced pressure.

rllhe compressor 41 is started after the valve 24 is again opened and the supply of 'gas from the cylinder 22 moderated as distillation proceeds and more recovered gas is supplied by the compressor 41.

rl`he distilling temperatures should be the lowest at which the material underl treat-F ment distills freely'. For crude stearic acid this range is about 450 F. to 480' F.

i As theadsorbent, a' sulphuric acid-activated clay of the'smectite or bentonite type `is preferred, although fullers earth of good quality can be used. By far the best .results are obtairied with activated clays, however. A proportion of dccolorizinpl carbon may be addedto the clay if desired', but is seldom focacce necessary. l prefer to use the acid-activated clay' known commercially asv Filtrol. lt

is made by a process somewhat similar to` that disclosed by Prutzman in U. vS. Patent No. 1,397,113.

` The remainder of the distillation, including separation of fatty acids from each other or from fixed fat, may be carried out by any skilled person in possession of the above directions, the condensing features of the process bein entirely conventional. The residue left 1n the still will be found to be a loose powder, easily removed.

In using `the apparatus of Fig. 2, the amount of adsorbent to be distributed on the shelves or plates may range from 1% to 10% by-weight of the fatty material to be distilled. Care should be taken to distribute it evenly on the shelves. lt is to be understood that fresh or reviviied adsorbent will usually have to be employed for each batch distilled. The carborundum plates' will usually require Washing withbenzine or otherfat solvent after a run. Monel metal and-bronze are among the suitable materials. from which the still may be made.

The distillates will be found to be practi cally waterwhite and of exceptional freedom from unsaponifiable matter and iso-oleic or hydro-stearic acids.

Example, using apparatus of Fig. 1,-

Five hundred ounds of commercial free fatty acids, mainly with 5% by weight'of Filtrol, acid-activated clay, are placed inthe Monel metal still. The temperature'is raised gradually, the fatty acids beginning to distil as low as 350 F. The mass is constantly agitated by the injection into it of C heated not to exceed 500 F. The amount of gas injected is, not critical but is sufficient to give lively agitation of the still contents.` The moisture y present in the fat is removed by the action lof the stream of gas before the distillation of fatty acid actually'begins. The presence of moisture in fatty material during actual distillation, as in the case of steam distillation,"has been found to be injurious. `Distillation is continued below 500 F. until the mass in the still is completely dry and powdery. The recovery of light colored free fatty acid in the condenser may be as high as 98%. By the term inert gas as used in theI specificationI and claims, l exclude both hydrogen and steam, neither of which is strictly inert.

l claim as my invention:

1. A process of recovering fatty acids from fatty material containing same ywhich comprises: addingv an active decolorizing agent to said material; subjecting the mix- 'ture so produced to sufficient temperature to palmitic and stearic,

12. process of recovering fatty acids' from fatty material containing same .which comprises: adding lan active decolorizing agent to said material; subjecting the mixture' so produced to sufficient temperature to v cause thefatty acids to distill off; agitatingl 1 acids.

the mixture'with carbon'dioxide gas during said distillation; and condensing said fatty A' process of recovering fatty acids from fatty material containing same which comprises: adding an active decolorizing agent to said material; 'subjecting the mixture so produced t sufficient temperature to v cause the fatty acids to distill 0H maintaining a partial vacuum on the still during said distillation; agitating the mixture with an inert gas during said. distillation; and condensing said fatty acids.

4.A process of recovering fatty acids from fatty-material containing same which oomprises: adding an active decolorizing agent tosaid materialsubjecting the mixture so produced to suilicient temperature to cause the fatty acids to distill olf; maintaining a partial vacuum on the still during said distillation; agitating the mixture with carbon dioxidev gas during said distillation; and coni densingsaid fatty acids,

5. A process of recovering fatty acids from fatty material containing same Which comprises; adding an active decolorizing agent to said material; subjecting'the mixture so produced to sufficient temperature to cause lthe fatty acids to distill off agitating the mixture with an inert gas during said distillation, said gas being preheated prior to its introduction into the still; and

` y, condensing said fatty acids. 40

. 6. A process of recovering fatty acids from" fatty material containing same which compriseszuadding an active .decolorizing agent to said material; subjecting the mix-- ture so produced to suiicient temperature to I acids to distill off.; agitating the mixturevwith carbon dioxide gas during said distillation, saidgas being preheated priorhto its introduction into the still; and condensing said fatty acids.

v7. A process of recovering fatty acids from Vfatty material containing same Whic comprises:

cause the fatty l agent ,to said material; subjecting the mixcom rises G5 P ...Q ture so produced to sufficient temperature tocause the fatty acids to distill oft' maintaining a partialvacuum on the still during said distillation.; agitating the mixture with n inert4 gas durmg said distillation, said gas .beingU preheated prior to its introduction intothe still; and condensing said fatty acids. L

.A4 process Iof recovering fatty acids from; fatty material containing same which `adding an active decolorizing agent to said material; subjecting the mixture so produced to sufficient temperature' adding Van active decoloriz-ing 

